Polarizer, display panel including the same and method of manufacturing the same

ABSTRACT

A polarizer includes a buffer member and linear metal patterns. The buffer member includes protrusions. Each protrusion has downwardly-increasing width. The buffer member is formed of polymer. The linear metal patterns, spaced apart from each other, are extended in a first direction. Each linear metal pattern covers a respective protrusion.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. § 119 to Korean PatentApplication No. 10-2014-0148420, filed on Oct. 29, 2014, in the KoreanIntellectual Property Office, the disclosure of which is incorporated byreference herein in its entirety.

TECHNICAL FIELD

The present invention relates to a wire grid polarizer, a method ofmanufacturing the polarizer and a display panel including the polarizer.

DISCUSSION OF THE RELATED ART

Polarizers control transmittance of light. The polarizers may transmit apolarizing component parallel to a transmitting axis, and may absorb orreflect a polarizing component perpendicular to the transmitting axis.

The polarizers include an absorbing polarizer and a reflectivepolarizer. The reflective polarizer reflects a specific polarizingcomponent of an incident light for polarization. The reflectivepolarizing component of the incident light may be reused by a reflectiveplate of a backlight assembly to increase brightness of a displaydevice.

SUMMARY

According to an exemplary embodiment of the present invention, apolarizer includes a buffer member and linear metal patterns. The buffermember includes protrusions. Each protrusion has downwardly-increasingwidth. The buffer member is formed of polymer. The linear metalpatterns, spaced apart from each other, are extended in a firstdirection. Each linear metal pattern covers a respective protrusion.

According to an exemplary embodiment of the present invention, a methodof manufacturing a polarizer is provided as follows. A buffer layerincluding a polymer and a metal layer are formed. The metal layer isformed on the buffer layer. Linear metal patterns and a plurality ofprotrusions are formed from the metal layer and the buffer layer,respectively, by pressing the metal layer and the buffer layer using amold having a pressing pattern. At least a portion of each protrusion isinserted into a respective metal pattern.

According to an exemplary embodiment of the present invention, a displaypanel includes a first substrate, a second substrate facing the firstsubstrate and a liquid crystal layer disposed between the firstsubstrate and the second substrate. The first substrate includes apolarizer including a plurality of linear metal patterns, and a buffermember, formed of polymer, having a plurality of protrusions. A portionof each protrusion is inserted into a respective linear metal pattern.Each protrusion has a tapered shape.

According to an exemplary embodiment of the present invention, a displaypanel includes a buffer member and metal lines. The buffer memberincludes protrusions. Each protrusion is protruded from an upper surfaceof the buffer member, and the protrusions cause the buffer member tohave a corrugated surface. The metal lines are disposed on thecorrugated surface of the buffer member. Each protrusion is enclosed bya respective metal line, and two adjacent metal lines expose a part ofthe upper surface of the buffer member therebetween.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the inventive concept will become moreapparent by describing in detail exemplary embodiments thereof withreference to the accompanying drawings of which:

FIG. 1 is a cross-sectional view of a polarizer according to anexemplary embodiment of the present invention;

FIG. 2 is a plan view of a polarizer according to an exemplaryembodiment of the present invention;

FIG. 3 is an enlarged cross-sectional view of region ‘A’ of FIG. 1;

FIGS. 4 to 7 are cross-sectional views illustrating a method ofmanufacturing a polarizer illustrated in FIG. 1 according to anexemplary embodiment of the present invention;

FIG. 8 is a perspective view of a pressing process using a roller;

FIG. 9 is a cross-sectional view of a polarizer according to anexemplary embodiment of the present invention;

FIGS. 10 and 11 are cross-sectional views illustrating a method ofmanufacturing the polarizer illustrated in FIG. 9 according to anexemplary embodiment of the present invention;

FIGS. 12 to 14 are cross-sectional views illustrating a method ofmanufacturing a polarizer according to an exemplary embodiment of thepresent invention;

FIG. 15 is a cross-sectional view of a polarizer according to anexemplary embodiment of the present invention;

FIG. 16 is a cross-sectional view of a polarizer according to anexemplary embodiment of the present invention;

FIGS. 17 and 18 are cross-sectional views illustrating a method ofmanufacturing the polarizer of FIG. 16 according to an exemplaryembodiment of the present invention;

FIG. 19 is a cross-sectional view of a polarizer according to anexemplary embodiment of the present invention;

FIGS. 20 and 21 are cross-sectional views illustrating a method ofmanufacturing the polarizer of FIG. 19 according to an exemplaryembodiment of the present invention;

FIGS. 22 to 24 are cross-sectional views of polarizers according toexemplary embodiments of the present invention;

FIG. 25 is a cross-sectional view of a display panel according to anexemplary embodiment of the present invention;

FIG. 26 is a cross-sectional view of a display panel according to anexemplary embodiment of the present invention; and

FIG. 27 is a cross-sectional view of a display panel according to anexemplary embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention will be described belowin detail with reference to the accompanying drawings. However, thepresent invention may be embodied in different forms and should not beconstrued as limited to the embodiments set forth herein. In thedrawings, the thickness of layers and regions may be exaggerated forclarity. It will also be understood that when an element is referred toas being “on” another element or substrate, it may be directly on theother element or substrate, or intervening layers may also be present.It will also be understood that when an element is referred to as being“coupled to” or “connected to” another element, it may be directlycoupled to or connected to the other element, or intervening elementsmay also be present. Like reference numerals may refer to the likeelements throughout the specification and drawings.

FIG. 1 is a cross-sectional view of a polarizer according to anexemplary embodiment. FIG. 2 is a plan view of a polarizer according toan exemplary embodiment. FIG. 3 is an enlarged cross-sectional view ofthe region ‘A’ of FIG. 1.

Referring to FIGS. 1 and 2, a polarizer includes a base substrate 10 a,a buffer member 11 a disposed on the base substrate 10 a, and a wiregrid array disposed on the buffer member 11 a. The wire grid arrayincludes a plurality of linear metal patterns 13 a extending in a firstdirection D1 and spaced apart from each other in a second direction D2crossing the first direction D1. The buffer member 11 a includes aprotrusion 12 a. At least a portion of the protrusion 12 a is insertedinto the linear metal pattern 13 a.

The base substrate 10 a may include a glass substrate, a quartzsubstrate, a sapphire substrate, a plastic substrate or the like. Theplastic substrate may include polyimide, polyethylene terephthalate,polyethylene naphthalate, polyvinyl chloride or the like.

The base substrate 10 a may be removed after the wire grid array isformed.

If the buffer member 11 a has a sufficient thickness, the base substrate10 a may be omitted in a manufacturing of the wire grid array. In thiscase, the removal of the base substrate 10 a after the formation of thewire grid array may be omitted.

The buffer member 11 a includes a polymer so that the buffer member 11 ais resilient. The polymer may include thermoplastic resin orthermosetting resin. For example, the buffer member 11 a may includepolymethylmethacrylate, polydimethyl siloxane, polycarbonate,polyethylene terephthalate, polystyrene, polyethylene, polypropylene,polyvinylalcohol or the like. The polymer may be modified or copolymers.

In an exemplary embodiment, the buffer member 11 a may include a polymerhaving a rubber phase at a room temperature and having a softening pointequal to or less than about 50° C. For example, the buffer member 11 amay include polydimethyl siloxane or a copolymer thereof. Examples ofthe polydimethyl siloxane copolymer may include polydimethylsiloxane/polycarbonate copolymer, polydimethylsiloxane/polymethylmethacrylate copolymer or the like.

Alternatively, the buffer member 11 a may include a polymer having asoftening point equal to or more than about 100° C. For example, thebuffer member 11 a may include polyethylene, polypropylene, polydimethylsiloxane or a copolymer thereof.

The buffer member 11 a may have various thickness, depending on athickness of the linear metal pattern 13 a and a manufacturing process.For example, a thickness of the buffer member 13 a may be about 30 nm toabout 500 nm.

The buffer member 11 a includes the protrusion 12 a protruding from anupper surface of the buffer member 11 a. For example, the buffer member11 a may include a base having a flat layer shape, and the protrusion 12a protruding from the base. The protrusion 12 a is inserted into thelinear metal pattern 13 a so that an upper surface and a side surface ofthe protrusion 12 a are covered by the linear metal pattern 13 a. In anexemplary embodiment, a substantially entire portion of the protrusion12 a may be inserted into the linear metal pattern 13 a.

The protrusion 12 a may extend in the same direction as the linear metalpattern 13 a extends. For example, the protrusion 12 a extends in thefirst direction D1. The protrusion 12 a is disposed to correspond toeach of the linear metal patterns 13 a. Thus, protrusions 12 a arearranged in the second direction D2 to be parallel to each other. Theprotrusion 12 a is formed with the buffer member 11 a in a unitarysingle unit. Thus, the protrusion 12 a and the buffer member 11 a areformed of the same material.

The wire grid array serves to perform polarization. For example, when alight is incident on the wire grid array, a component of the light,which is parallel to a transmitting axis of the wire grid array, may betransmitted, and a component of the light, which is perpendicular to thetransmitting axis of the wire grid array, may be reflected.

The linear metal pattern 13 a may include a metal. For example, thelinear metal pattern 13 a may include aluminum, gold, silver, copper,chromium, iron, nickel, titanium, molybdenum, tungsten or an alloythereof. In an exemplary embodiment, the linear metal pattern 13 a mayinclude aluminum, gold, silver or copper. In an exemplary embodiment,the linear metal pattern 13 a includes aluminum, which has relativelyhigh ductility and reflectivity. Furthermore, the linear metal pattern13 a may have a multiple-layered structure including different metallayers. Furthermore, the linear metal pattern 13 a may further include ametal oxide, a metal nitride or the like.

The linear metal patterns 13 a may have a pitch, a thickness and a linewidth such that the linear metal patterns 13 a serve to polarize light.

For example, a pitch of the linear metal patterns 13 a may be less thana wavelength of an incident light. For example, the pitch P of thelinear metal patterns 13 a may be equal to or less than about 400 nm forpolarizing a visible light. In an exemplary embodiment, the pitch P ofthe linear metal patterns 13 a may be equal to or less than about 150nm. For example, the pitch of the linear metal patterns 13 a may beabout 50 nm to about 150 nm.

In an exemplary embodiment, a thickness H of the linear metal pattern 13a may be defined as a length between an upper end of the protrusion 12 aand an upper end of the linear metal pattern 13 a. The thickness H ofthe linear metal pattern 13 a may be equal to or greater than about 80nm. In an exemplary embodiment, the thickness H may be about 80 nm toabout 300 nm.

Transmittance or refractivity of the wire grid array may depend on aratio of the line width to the pitch P. The line width may bedifferently defined depending on a shape of the linear metal pattern 13a and a size of the protrusion 12 a. For example, the line width may bedefined as a width W1 of a lower end of the linear metal pattern 13 a ora width W2 of an upper end of the linear metal pattern 13 a. The linearmetal pattern 13 a may have a tapered shape. Thus, the width W1 of thelower end may be greater than the width W2 of the upper end. In anexemplary embodiment, the line width may be less than or equal to about100 nm. For example, the line width may be about 20 nm to about 100 nm.

Referring to FIG. 3, the protrusion 12 a of the buffer member 11 a andthe linear metal pattern 13 a may have a tapered shape including a lowerend wider than an upper end.

Thus, a taper angle θ1 of the linear metal pattern 13 a, which isdefined by a side surface of the linear metal pattern 13 a and an uppersurface of the buffer member 11 a, and a taper angle θ2 of theprotrusion 12 a, which is defined by a side surface of the protrusion 12a and a horizontal line extending from the upper surface of the buffermember 11 a, may be less than about 90°. Furthermore, the taper angle θ2of the protrusion 12 a may be less than the taper angle θ1 of the linearmetal pattern 13 a.

While the linear metal pattern 13 a, shown in FIG. 1, has a taperedshape such that the width W1 of the lower end is greater than the widthW2 of the upper end, the present invention is not limited thereto. Theshape of the linear metal pattern 13 a may vary depending on, forexample, a shape of a mold. For example, a cross-section of the linearmetal pattern 13 a may have a substantially rectangular shape toincrease polarization.

Furthermore, while a cross-section of the protrusion 12 a has atrapezoid shape in FIGS. 1 to 3, the present invention is not limitedthereto. The cross-section of the protrusion 12 a may vary depending on,for example, a shape of a mold or a condition in a manufacturingprocess. For example, the cross-section of the protrusion 12 a may havea triangular shape, an arc shape or the like.

FIGS. 4 to 7 are cross-sectional views illustrating a method ofmanufacturing a polarizer of FIG. 1. FIG. 8 is a perspective view of apressing process using a roller.

Referring to FIGS. 4 and 5, a buffer layer BL is formed on a basesubstrate 10 a, and a metal layer ML is formed on the buffer layer BL.

The buffer layer BL may include polymethylmethacrylate, polydimethylsiloxane, polycarbonate, polyethylene terephthalate, polystyrene,polyethylene, polypropylene, polyvinylalcohol or a copolymer thereof.

A composition including the polymer dispersed in a solvent such as analcohol, a glycol, an ether or the like may be provided on the basesubstrate 10 a. The solvent may be removed through a drying process toform the buffer layer BL. In an exemplary embodiment, the buffer layerBL is first formed to a sheet shape, and the buffer layer BL is attachedto the base substrate 10 a, for example, through lamination. In anexemplary embodiment, a composition including a polymer resin, a curingagent and a polymerization initiator is provided on the base substrate10 a, and the composition may be cured through heat-curing orphoto-curing to form the buffer layer BL including a cured polymerresin.

The metal layer ML may include aluminum, gold, silver, copper, chromium,iron, nickel, titanium, molybdenum, tungsten or an alloy thereof. In anexemplary embodiment, the metal layer ML may include aluminum, gold,silver or copper. The metal layer ML may be formed through aconventional method for forming a metal layer, for example, sputtering,lamination or the like.

After the metal layer ML is formed, a mold 16 a including a pressingpattern 17 a is disposed on the metal layer ML to press the metal layerML. The pressing pattern 17 a approaches the metal layer ML in thepressing process.

The mold 16 a includes a material having a surface hardness higher thanthe metal layer ML. For example, the mold 16 a may include a materialhaving a high surface hardness, such as silicon, nickel, tungsten or thelike.

The pressing pattern 17 a extends in a direction. A plurality ofpressing patterns 17 a are arranged in a direction crossing theextending direction to be parallel with each other. A cross-section ofthe pressing pattern 17 a has a tapered shape so that a width of anupper end is greater than a width of a lower end. The pressing patterns17 a are spaced apart from each other to form a groove therebetween. Thegroove may have a shape substantially same as a linear metal pattern tobe formed in the pressing process.

Referring to FIGS. 5 and 6, as the mold 16 a is pressed to the metallayer ML, a shape of a pressing surface of the mold 16 a is transferredto the metal layer ML and the buffer layer BL. A portion of the metallayer ML and a portion of the buffer layer BL are deformed along theshape of the pressing surface of the mold 16 a. Although the bufferlayer BL has rubber resilience, the deformed portion of the buffer layerBL is covered by a plastically deformed portion of the metal layer MLand thus the deformed portion of the buffer layer BL keeps a protrudedshape. which contacts the lower end of the pressing pattern 17 a, maypenetrate into the buffer layer NL. In the process of transferring, themetal layer ML may be elongated along the deformed portion of the bufferlayer BL and the elongated metal layer ML is disconnected in an areacontacting the lower end of the pressing pattern 17 a.

As a result, a wire grid array including a plurality of linear metalpatterns 12 a spaced apart from each other and arranged parallel witheach other. Furthermore, the buffer layer BL is partially pressed toform a buffer member 11 a including a protrusion 12 a inserted into thelinear metal pattern 13 a. Even if the buffer member 11 a include apolymer having a rubber phase at a room temperature, because theprotrusion 12 a is restrained by the linear metal pattern 13 a, a shapeof the protrusion 12 a may be maintained. Because the protrusion 12 a isformed by penetration of the pressing pattern 17 a, the protrusion 12 amay have a taper angle less than the linear metal pattern 13 a.

In the process of pressing the mold 16 a, the metal layer ML and thebuffer layer BL may be heated. For example, if the buffer layer BLincludes a polymer having a solid phase at a room temperature, and ifthe pressing process is performed at a room temperature, the bufferlayer BL may have insufficient flexibility. When the polymer having asolid phase at a room temperature is heated at temperature near a glasstransition temperature or a softening point, the phase of the polymer ischanged to a rubber phase. Thus, the buffer layer BL may providesufficient flexibility and resilience.

The heating temperature may vary depending on properties of the polymerof the buffer layer BL. For example, the heating temperature may be, butis not limited to, about 100° C. to about 200° C.

In an exemplary embodiment, heat HEAT is provided through the basesubstrate 10 a. For example, a conveyer belt transferring the basesubstrate 10 a may include a heart to heat the base substrate 10 a.Alternatively, the mold 16 a may be heated. The heat may be providedbefore the mold 16 a approach the base substrate 10 a.

In an exemplary embodiment, the mold 16 a may have a plate shape.Alternatively, the mold 16 a, shown in FIG. 8, may have a roller shape.The mold having a roller shape may reduce manufacturing time inmanufacturing a large-sized polarizer.

Referring to FIG. 7, the mold 16 a is pulled off from the buffer member11 a and the wire grid array.

According to an exemplary embodiment, a mold may be directly pressedinto a metal layer disposed on a buffer layer that provides resilienceand flexibility to form a wire grid array. Thus, an etching processusing a mask may be omitted. Thus, damage to a wire grid pattern due toan etching process may be prevented or reduced. Furthermore,manufacturing time for a polarizer may be reduced.

Furthermore, since a protrusion of a buffer member is inserted into alinear metal pattern, a lower surface of the linear metal pattern has anuneven cross-section. Thus, when the polarizer is employed in a displaysubstrate, reflection of an external light may be prevented or reducedto increase display quality.

Furthermore, the polarizer may include a buffer member havingflexibility, or may be directly formed on a flexible substrate. Thus,the polarizer may be used for a flexible display device.

FIG. 9 is a cross-sectional view of a polarizer according to anexemplary embodiment of the present invention. FIGS. 10 and 11 arecross-sectional views illustrating a method of manufacturing thepolarizer illustrated in FIG. 9.

In the following exemplary embodiments, any duplicated explanation forelements having same functions and including same materials as thepolarizer of FIGS. 1 to 3 may be omitted.

Referring to FIG. 9, a polarizer includes a base substrate 10 b, abuffer member 11 b disposed on the base substrate 10 b, and a wire gridarray disposed on the buffer member 11 b. The wire grid array includes aplurality of linear metal patterns 15 extending in a first direction andspaced apart from each other in a second direction crossing the firstdirection. The buffer member 11 b includes a plurality of protrusions 12b. Each protrusion 12 b is covered by a respective linear metal pattern15. In an exemplary embodiment, at least a portion of each protrusion 12b is inserted into a respective linear metal pattern 15.

The linear metal pattern 15 includes a lower metal pattern 13 b and anupper protective pattern 14 covering the lower metal pattern 13 b. Theprotrusion 12 b of the buffer member 11 b is inserted into the lowermetal pattern 13 b. The upper protective pattern 14 covers an uppersurface and a side surface of the lower metal pattern 13 b.

The lower metal pattern 13 b and the upper protective pattern 14 areformed of different materials from each other. For example, the lowermetal pattern 13 b may include aluminum, gold, silver, copper or analloy thereof. The upper protective pattern 14 may include molybdenum,tungsten, titanium, nickel, an alloy thereof, an oxide thereof or anitride thereof. The upper protective pattern 14 may serve to protectthe lower metal pattern 13 b in the following processes after theformation of the lower metal pattern 13 b.

Referring to FIGS. 10 and 11, a buffer layer BL is formed on a basesubstrate 10 b. A first metal layer ML1 is formed on the buffer layerBL. A second metal layer ML2 is formed on the first metal layer ML1. Inan exemplary embodiment, the second metal layer ML2 is thinner than thefirst metal layer ML1.

The buffer layer BL may include a polymer exemplified in the above.

The first metal layer ML1 may include aluminum, gold, silver, copper oran alloy thereof. The second metal layer ML2 may include molybdenum,tungsten, titanium, nickel or an alloy thereof.

After the second metal layer ML2 is formed on the base substrate 10 b,the base substrate 10 b is pressed using a mold 16 b having a pressingpattern 17 b. In the pressing, the first and second metal layers ML1 andML2, and the base layer BL are pressed to the extent that the structureof FIG. 9 is formed.

As a result, a wire grid array including a plurality of linear metalpatterns spaced apart from each other, each of the linear metal patternsincluding a lower metal pattern 13 b and an upper protective pattern 14,is formed.

FIGS. 12 to 14 are cross-sectional views illustrating a method ofmanufacturing a polarizer according to an exemplary embodiment of thepresent invention.

Referring to FIGS. 12 and 13, a mold 16 c including a pressing pattern17 c is used for pressing a metal layer to form a linear metal pattern13 c and a buffer member 11 c including a protrusion 12 c. According toa pressing process condition, linear metal patterns 13 c, shown in FIG.13c , are connected to each other by a connection portion 15 whichremain after the pressing process.

As illustrated in FIG. 14, the connection portion 15 is removed using anetching process. For example, after the mold 16 c is lifted off from thebase substrate 10 c, an etchant ETCH is provided so that the connectionportion 15 is removed. The linear metal pattern 13 c is partiallyremoved in the etching process of removing the connection portion 15. Inthe process of removing the connection portion 15, a thickness of thelinear metal pattern 13 c is reduced, and a spacing between two adjacentliner metal patterns 13 c increases. The etching process may include anisotropic etching process or an anisotropic etching process. Forpreventing damage of a profile of the linear metal pattern 13 c, theconnection portion 15 may be removed through an anisotropic etchingprocess.

Alternatively, the connection portion 15 need not be removed if theconnection portion 15 is thin to the extent that visible light passesthrough the connection portion 15. For example, if the connectionportion 15 including aluminum may have a thickness equal to or less thanabout 10 nm, visible light may pass through the connection portion 15and thus the connection portion need not be removed. Thus, the wire gridarray having the connection portion 15 may serve to polarize incominglight.

FIG. 15 is a cross-sectional view of a polarizer according to anexemplary embodiment of the present invention.

Referring to FIG. 15, a polarizer includes a base substrate 10 d, abuffer member 11 d disposed on the base substrate 10 d, a plurality oflinear metal patterns 13 d disposed on the buffer member 11 d, and aprotective layer 20 disposed on the linear metal patterns 13 d. Thelinear metal patterns 13 d extend in a first direction and spaced apartfrom each other in a second direction crossing the first direction. Thebuffer member 11 d includes a protrusion 12 d. Each linear metal pattern13 d covers a respective protrusion 12 d. In an exemplary embodiment, atleast a portion of each protrusion 12 d may be inserted into arespective linear metal pattern 13 d.

The protective layer 20 has a continuous film shape. The protectivelayer 20 protects the linear metal patterns 13 d. The protective layer30 has a shape of a flat thin film opposite to the buffer member 11 d.Thus, an air gap 50 is formed between adjacent linear metal patterns 13d. The air gap 50 may increase a refractivity difference of thepolarizer to improve polarizing characteristics.

The protective layer 20 may be formed of an inorganic insulatingmaterial including silicon oxide (SiOx), silicon oxicarbide (SiOC),silicon nitride (SiNx) or the like. A thickness of the protective layer20 may be about 100 nm to about 1 um. For example, the protective layer20 may be formed using a chemical vapor deposition process.

While the polarizer includes the protective layer having a shape of aflat thin film such that an air gap is formed between adjacent linearpatterns in the exemplary embodiment, a polarizer according to anotherexemplary embodiment may include an organic insulation layer or aninorganic insulation layer, which fills the gap 50 between the linearpatterns.

FIG. 16 is a cross-sectional view of a polarizer according to anexemplary embodiment of the present invention. FIGS. 17 and 18 arecross-sectional views illustrating a method for manufacturing thepolarizer of FIG. 16.

Referring to FIG. 16, a polarizer includes a base substrate 10 e, abuffer member 11 e disposed on the base substrate 10 e, a wire gridarray disposed on the buffer member 11 e, and a reflective part 22formed of the same layer as the wire grid array. The wire grid arrayincludes a plurality of linear metal patterns 13 e extending in a firstdirection and spaced apart from each other in a second directioncrossing the first direction. The buffer member 11 e includes a firstprotrusion 12 e and a second protrusion 21. At least a portion of thefirst protrusion 12 e is inserted into the linear metal pattern 13 e. Atleast a portion of the second protrusion 22 is inserted into thereflective part 22.

The reflective part 22 has a width greater than the linear metal pattern13 e. The second protrusion 21 has a width greater than the firstprotrusion 12 e. The polarizer including the reflective part 22 mayreflect a light incident thereon to increase reuse of a light in aliquid crystal display panel.

Referring to FIGS. 17 and 18, a buffer layer BL is formed on a basesubstrate 10 e, and a metal layer ML is formed on the buffer layer BL.

After the metal layer ML is formed, a mold 16 e including a pressingpattern 17 e is disposed on the metal layer ML to press the metal layerML. A plurality of pressing patterns 17 e are spaced apart from eachother by a first distance in a first area R1 of the mold 17 e to form awire grid pattern, and are spaced apart from each other by a seconddistance greater than the first distance in a second area R2 of the mold17 e to form a reflective groove 18.

As a result, a wire grid array and a reflective part 22 formed of thesame layer as the wire grid array are formed.

FIG. 19 is a cross-sectional view of a polarizer according to anexemplary embodiment. FIGS. 20 and 21 are cross-sectional viewsillustrating a method of manufacturing the polarizer illustrated in FIG.19.

Referring to FIG. 19, a polarizer includes a base substrate 10 f, arubber-phase buffer member 23 disposed on the base substrate 10 f, asolid-phase buffer member 11 f disposed on the rubber-phase buffermember 23, and a wire grid array disposed on the solid-phase buffermember 11 f. The wire grid array includes a plurality of linear metalpatterns 13 f extending in a first direction and spaced apart from eachother in a second direction crossing the first direction. Thesolid-phase buffer member 11 f includes a protrusion 12 f. At least aportion of the protrusion 12 f is inserted into the linear metal pattern13 f.

The solid-phase buffer member 11 f and the rubber-phase buffer member 23are formed of different materials.

For example, the rubber-phase buffer member 23 may include a polymerhaving a rubber phase at a room temperature. For example, therubber-phase buffer member 23 may include a polymer having a softeningpoint equal to or less than about 50° C. For example, the rubber-phasebuffer member 23 may include polyethylene, polypropylene, polydimethylsiloxane or a copolymer thereof. In an exemplary embodiment, therubber-phase buffer member 23 may include polydimethyl siloxane or acopolymer thereof.

The solid-phase buffer member 11 f may include a polymer having a solid(glass) phase at a room temperature. For example, the solid-phase buffermember 11 f may include a polymer having a softening point equal to ormore than about 100° C. For example, the solid-phase buffer member 11 fmay include polyethylene terephthalate, polycarbonate or a copolymerthereof.

The rubber-phase buffer member 23 may include a protrusion 24overlapping the protrusion 12 f of the solid-phase buffer member 11 f.

Referring to FIGS. 20 and 21, a first buffer layer BL1, a second bufferlayer BL2 and a metal layer ML are formed on a base substrate 10 f.

The first buffer layer BL1 includes a polymer having a rubber phase at aroom temperature, for example, having a softening point equal to or lessthan about 50° C. The second buffer layer BL2 having a solid phase at aroom temperature, for example, having a softening point equal to or morethan about 100° C.

After the metal layer ML is formed, a mold 16 f including a pressingpattern 17 f is disposed on the metal layer ML to press the metal layerML.

In the process of pressing the metal layer ML, the second buffer layerBL2 is heated by a temperature equal to or more than the softening pointof second buffer layer BL2 and turned into a rubber phase. Thus, thepressing pattern 17 f may penetrate into the metal layer ML to theextent that the metal layer ML is disconnected by the pressing pattern17.

When the mold 16 f is removed, a temperature is reduced. Thus, asolid-phase buffer member 11 f and a protrusion 12 f formed from thesecond buffer layer BL2 is solidified. Thus, arrangement of a wire gridarray disposed on the solid-phase buffer member 11 f may be preventedfrom changing.

A rubber-phase buffer member 23 formed from the first buffer layer BL1provides resilience and flexibility to a polarizer at a room temperatureto prevent separation by an external force and to increase flexibilityof the polarizer.

In an exemplary embodiment, the rubber-phase buffer member 23 includesthe protrusion 24 to form an uneven upper surface. Alternatively, therubber-phase buffer member 23 does not include the protrusion 24 so thatthe rubber-phase buffer member 23 has a flat upper surface according toproperties of a polymer included therein or manufacturing conditions.

In an exemplary embodiment, the linear metal patterns have a taperedshape. The present invention is not limited thereto, and may havevarious shapes.

For example, referring to FIG. 22, a polarizer includes a base substrate10 g, a buffer member 11 g disposed on the base substrate 10 g, and awire grid array disposed on the buffer member 11 g and including alinear metal pattern 13 g. The buffer member 11 g includes a protrusion12 g inserted into the linear metal pattern 13 g. The linear metalpattern 13 g has a substantially rectangular shape. Thus, a side surfaceof the linear metal pattern 13 g may extend in a direction substantiallyperpendicular to an upper surface of the base substrate 10 g. Therectangular shape of the linear metal pattern 13 g may increasepolarization properties of the polarizer.

Referring to FIG. 23, a polarizer includes a base substrate 10 h, abuffer member 11 h disposed on the base substrate 10 h, and a wire gridarray disposed on the buffer member 11 h and including a linear metalpattern 13 h. The buffer member 11 h includes a protrusion 12 h insertedinto the linear metal pattern 13 h. The linear metal pattern 13 hincludes a lower portion wider than an upper portion. The side surfaceof the upper portion extends in a direction substantially perpendicularto an upper surface of the base substrate 10 h. The side surface of thelower portion extends to form an angle less than about 90° with theupper surface of the base substrate 10 h. The linear metal pattern 13 hmay increase polarization properties of the polarizer. Furthermore,since the linear metal pattern 13 h is formed by a mold having a sharpend, a metal layer may be easily disconnected.

Referring to FIG. 24, a polarizer includes a base substrate 10 i, abuffer member 11 i disposed on the base substrate 10 i, and a wire gridarray disposed on the buffer member 11 i and including a linear metalpattern 13 i. The buffer member 11 i includes a protrusion 12 i insertedinto the linear metal pattern 13 i. The linear metal pattern 13 iincludes an upper portion and a lower portion having a side surface in adifferent direction from the upper portion. For example, an upperportion has a taper angle smaller than the lower portion. The linearmetal pattern 13 i includes two portions having different taper angles.Alternatively, the linear metal pattern 13 i may have a moth-eye shapesuch that a taper angle is gradually reduced from an lower end toward anupper end. The linear metal pattern 13 i may reduce reflectance of alight incident thereon to achieve anti-reflectance.

According to exemplary embodiments, a wire grid array pattern may bedirectly transferred by a mold without an etching process using a mask.Thus, a wire grid array pattern may have various profiles as desired.

FIG. 25 is a cross-sectional view of a display panel according to anexemplary embodiment. FIG. 26 is a cross-sectional view of a displaypanel according to an exemplary embodiment. FIG. 27 is a cross-sectionalview of a display panel according to an exemplary embodiment.

Referring to FIG. 25, a display panel includes a first substrate 100, asecond substrate 200 facing the first substrate 100 and a liquid crystallayer interposed between the first substrate 100 and the secondsubstrate 200. The display panel receives a light LIGHT from a lightsource module LS disposed under the display panel to display an image.

The first substrate 100 includes a first polarizer and a thin filmtransistor array. A light incident on the first polarizer from the lightsource module LS may be partially transmitted and partially reflected.The reflected light by the first polarizer may enter the light sourcemodule LS, and may be reflected by a reflective member of the lightsource module LS to re-enter the display panel.

The first substrate 100 includes a first base substrate 110, a firstbuffer member 111, a wire grid array including a first linear metalpattern 113, a first protective layer 114, a gate electrode GE, a gateinsulation layer 115, an active pattern AP, a source electrode SE, adrain electrode DE, a passivation layer 116, an organic insulation layer117 and a pixel electrode PE.

The first buffer member 111 is disposed between the first base substrate110 and the wire grid array. The first buffer member 111 includes apolymer. The first buffer member 111 includes a protrusion 112 upwardlyprotruding from an upper surface of the first buffer member 111. Atleast a portion of the protrusion 112 is inserted into the first linearmetal pattern 113 so that an upper surface and a side surface of theprotrusion 112 are covered by the first linear metal pattern 113.

The protrusion 112 and the first linear metal pattern 113 extend in afirst direction. A plurality of protrusions 112 and a plurality of firstlinear metal patterns 113 are arranged in a second direction crossingthe first direction to be parallel with each other. The protrusion 112and the first buffer member 111 are formed in a single unitary unitwhich is formed of the same material.

The wire grid array may serve to polarize the incident light LIGHT. Thefirst linear metal pattern 113 includes a metal. In an exemplaryembodiment, the first linear metal pattern 113 may be formed of amulti-layered structure including different metal layers. In this case,the first linear metal pattern 113 may further include a metal oxide, ametal nitride or the like.

The protrusion 112 and the first linear metal pattern 113 may have atapered shape of which a lower end is wider than an upper end. A taperangle of the protrusion 112 may be less than a taper angel of the firstlinear metal pattern 113.

The first protective layer 114 is formed on the wire grid array toprotect the wire grid array.

The first polarizer is substantially the same as the polarizer of FIG.15. Thus, the description of the first polarizer will be omitted.

The gate electrode GE, the active pattern AP, the source electrode SEand the drain electrode DE form a thin film transistor. The thin filmtransistor is electrically connected to the pixel electrode PE. The thinfilm transistor is disposed between the first polarizer and the firstbase substrate 111. The thin film transistor array may be formed on thefirst polarizer after the first polarizer is formed on the first basesubstrate 111.

The gate electrode GE is disposed on the first protective layer 114. Thegate electrode GE is electrically connected to a gate line that extendsin a direction on the first base substrate 111. The gate electrode GEmay include aluminum, copper, chrome, molybdenum, tungsten, titanium,gold, silver, nickel or an alloy thereof. Furthermore, the gateelectrode GE may have a single-layered structure or a multiple-layeredstructure including different metal layers. For example, the gateelectrode GE may have a triple-layered structure ofaluminum/molybdenum/aluminum or a double-layered structure including anupper layer of copper, and a lower layer of titanium.

The gate insulation layer 115 covers the gate electrode GE. The gateinsulation layer 115 may include an inorganic insulation material suchas silicon oxide, silicon nitride or the like. The gate insulation layer115 may have a single-layered structure or a multiple-layered structureincluding different materials. For example, the gate insulation layer115 may include an upper layer including silicon oxide and a lower layerincluding silicon nitride.

The active pattern AP is disposed on the gate insulation layer 115, andoverlaps the gate electrode GE. The active pattern AP forms a channelbetween the source electrode SE and the drain electrode DE. The activepattern AP may include amorphous silicon, polysilicon, oxidesemiconductor or the like. When the active pattern AP includes amorphoussilicon, the active pattern AP may further include an ohmic contactlayer contacting the source electrode SE and the drain electrode DE. Theoxide semiconductor may include a multi-component metal oxide such asindium gallium oxide, indium gallium zinc oxide or the like.

The source electrode SE is electrically connected to a data line. Thedata line, the source electrode SE and the drain electrode DE may beformed of the same metal layer. The source electrode SE may includealuminum, copper, chrome, molybdenum, tungsten, titanium, gold, silver,nickel or an alloy thereof. Furthermore, the source electrode SE mayhave a single-layered structure or a multiple-layered structureincluding different metal layers. For example, the source electrode SEmay have a triple-layered structure of aluminum/molybdenum/aluminum or adouble-layered structure including an upper layer of copper, and a lowerlayer of titanium. Alternatively, the source electrode SE may include abarrier layer including a metal oxide. For example, the source electrodeSE may include a copper layer and a metal oxide layer disposed on orunder the copper layer. The metal oxide layer may include indium zincoxide, indium gallium oxide, gallium zinc oxide or the like.

The passivation layer 116 covers the source electrode SE, the drainelectrode DE and the gate insulation layer 115. The passivation layer116 may include an inorganic insulation material such as silicon oxide,silicon nitride or the like.

The organic insulation layer 117 is disposed on the passivation layer116 to planarize the substrate. The organic insulation layer 117 mayinclude an organic insulation material such as an acryl resin, a phenolresin or the like. Alternatively, the passivation layer 116 and/or theorganic insulation layer 117 may be omitted.

The pixel electrode PE is disposed on the organic insulation layer 117.The pixel electrode PE is electrically connected to the drain electrodeDE. A pixel voltage is applied to the pixel electrode PE through thethin film transistor so that an electric field is formed by a voltagedifference between the pixel voltage and a common voltage applied to acommon electrode.

In an exemplary embodiment, the pixel electrode PE passes through thepassivation layer 116 and the organic insulation layer 117 to contactthe drain electrode DE. The pixel electrode PE may include a transparentconductive material such as indium tin oxide, indium zinc oxide or thelike.

The second substrate 200 includes a second base substrate 210, a secondbuffer member 211 including a protrusion 212, a wire grid arrayincluding a second linear metal pattern 413, a second protective layer214, a light-blocking member BM, an overcoating layer OC and a commonelectrode CE.

The second polarizer including the second buffer member 211 includingthe protrusion 212, the second linear metal pattern 213 and the secondprotective layer 214 is substantially the same as the first polarizer.The first and second polarizes are arranged to face each other. Forexample, the protrusions 112 and 212 of the first and second buffermembers face each other in opposite directions. Thus, the description ofthe second polarizer will be omitted.

The second linear metal pattern 213 extends in the same direction as thefirst linear metal pattern 113. The present invention is not limitedthereto. For example, the second linear metal pattern 213 may extend ina different direction from the first linear metal pattern 113, forexample, in a perpendicular direction to the first linear metal pattern113.

The light-blocking member BM is disposed on the second protective layer214. The light-blocking member BM may be a black matrix having a matrixshape. The light-blocking member BM overlaps the thin film transistor.

The color filter CF is disposed on the second protective layer 214. Thecolor filter CF faces and overlaps the pixel electrode PE. The colorfilter CF may include a red filter, a green filter, a blue filter, acyan filter, a yellow filter, a magenta filter, a white filter or thelike.

The overcoating layer OC covers the light-blocking member BM and thecolor filter CF. The overcoating layer OC may include an organicinsulation material.

The common electrode CE is disposed on the overcoating layer OC andoverlaps the pixel electrode PE. The common electrode CE may include atransparent conductive material such as indium tin oxide, indium zincoxide or the like.

In an exemplary embodiment, the pixel electrode PE is disposed in thefirst substrate 100, and the common electrode CE is disposed in thesecond substrate 200. The present invention is not limited thereto. Forexample, a pixel electrode and a common electrode may be disposed in thesame substrate. A color filter and/or a light-blocking member may bedisposed in a substrate having a thin film transistor substrate.

According to an exemplary embodiment, the display panel includes a wiregrid polarizer. The wire gird polarizer may share a base substrate withdisplay substrates to reduce a thickness of the display panel, and maysubstitute for an absorptive polarizer, which is expensive.

Furthermore, the polarizer may be manufacture without an etching processusing a mask. Thus, profile of a metal pattern may be protected, andmanufacturing efficiency may be increased.

Furthermore, a lower surface of a linear metal pattern of the polarizerforms an uneven surface due to a protrusion of a buffer member. Theuneven surface may prevent reflectance of an external light to increasedisplay quality of the display panel.

Referring to FIG. 26, a display panel includes a first substrate 300, asecond substrate 400 facing the first substrate 300 and a liquid crystallayer interposed between the first substrate 300 and the secondsubstrate 400.

The first substrate 300 includes a first polarizer and a thin filmtransistor array. The first substrate 300 includes a first basesubstrate 310, a first buffer member 311 including a protrusion 312, awire grid array including a first linear metal pattern 313, a firstprotective layer 314, a gate electrode GE, a gate insulation layer 315,an active pattern AP, a source electrode SE, a drain electrode DE, apassivation layer 316, an organic insulation layer 317 and a pixelelectrode PE.

The second substrate 400 includes a second base substrate 410, a secondbuffer member 411 including a protrusion 412, a wire grid arrayincluding a second linear metal pattern 413, a second passivation layer414, a light-blocking member BM, an overcoating layer OC and a commonelectrode CE.

The first substrate 300 is substantially the same as the first substrate100 illustrated in FIG. 25 except that the first base substrate 310 isdisposed between the first polarizer and the thin film transistor array,and that the first polarizer is vertically inversed. In this case, theprotrusions of 312 and 413 of the first and second buffer members 311and 411 face in the same direction.

The second substrate 400 is substantially the same as the secondsubstrate 200 of FIG. 25.

An uneven surface of the first linear metal pattern 313 faces the liquidcrystal layer. Thus, transmittance of a light provided to the firstsubstrate 300 from the light source module may be increased.

Referring to FIG. 27, a display panel includes a first substrate 500, asecond substrate 600 facing the first substrate 500 and a liquid crystallayer interposed between the first substrate 500 and the secondsubstrate 600.

The first substrate 500 includes a first polarizer and a thin filmtransistor array. The first substrate 500 includes a first basesubstrate 510, a first buffer member 511 including a protrusion 512, awire grid array including a first linear metal pattern 513, a firstprotective layer 514, a gate electrode GE, a gate insulation layer 515,an active pattern AP, a source electrode SE, a drain electrode DE, apassivation layer 516, an organic insulation layer 517 and a pixelelectrode PE.

The second substrate 600 includes a second base substrate 610, a secondbuffer member 611 including a protrusion 612, a wire grid arrayincluding a second linear metal pattern 613, a second passivation layer614, a light-blocking member BM, an overcoating layer OC and a commonelectrode CE.

The first substrate 500 is substantially the same as the first substrate100 of FIG. 25 except that the first substrate 500 further includes areflective part 519 formed of the same layer as the wire grid array andthat the first buffer member 511 further includes a second protrusion518, of which at least a portion is inserted into the reflective part519.

The second substrate 600 is substantially the same as the secondsubstrate 200 of FIG. 25.

The reflective part 519 is formed of the same material of the firstlinear metal pattern 513. Furthermore, the reflective part 519 has awidth greater than the first linear metal pattern 513. The reflectivepart 519 may be disposed in a light-blocking area. For example, thereflective part 519 overlaps a thin film transistor or thelight-blocking member BM.

When the first substrate 500 does not include the reflective part 519, alight entering the light-blocking area may be transmitted and absorbedby the light-blocking member BM. The reflective part 519 reflects thelight incident thereon so that the reflected light may be reused. Thus,a brightness of the display panel may be increased.

The present invention may be employed in various display devicesincluding a polarizer. For example, the present invention may beemployed in an organic light-emitting device or optical devices, whichinclude a polarizer.

While the present invention has been shown and described with referenceto exemplary embodiments thereof, it will be apparent to those ofordinary skill in the art that various changes in form and detail may bemade therein without departing from the spirit and scope of theinventive concept as defined by the following claims.

What is claimed is:
 1. A polarizer comprising: a buffer member having aplurality of protrusions each having a first thickness, wherein thebuffer member is formed of a polymer; and a plurality of linear metalpatterns spaced apart from each other and extended in a first direction,wherein each linear metal pattern entirely covers a respectiveprotrusion, wherein a second thickness between an upper surface of eachlinear metal pattern and an upper surface of a corresponding one of theprotrusions is greater than the first thickness, wherein each linearmetal pattern comprises a trapezoidal shape covering a top portion ofone of the protrusions, the trapezoidal shape comprises an extensioncovering a side of the one protrusion, and wherein an angle of theextension relative to an upper surface of the buffer member is an acuteangle and an angle of the side relative to the upper surface of thebuffer member is less than the acute angle.
 2. The polarizer of claim 1,wherein the linear metal patterns include aluminum, gold, silver,copper, chromium, iron, nickel, titanium, molybdenum, tungsten or analloy thereof.
 3. The polarizer of claim 1, wherein the buffer memberincludes polymethylmethacrylate, polydimethyl siloxane, polycarbonate,polyethylene terephthalate, polystyrene, polyethylene, polypropylene,polyvinylalcohol or a copolymer thereof.
 4. The polarizer of claim 1,wherein the linear metal pattern includes a lower metal pattern and anupper protective pattern covering the lower metal pattern, and whereinthe lower metal pattern includes aluminum, gold, silver, copper or analloy thereof, and the upper protective pattern includes nickel,titanium, molybdenum, tungsten, an alloy thereof, an oxide thereof or anitride thereof.
 5. The polarizer of claim 1, further comprising aconnection portion disposed between two adjacent linear metal patterns,wherein the connection portion is thin to the extent that light passesthrough the connection portion.
 6. The polarizer of claim 1, whereineach protrusion has a downwardly-increasing width.
 7. The polarizer ofclaim 1, further comprising: a protective layer disposed on the linearmetal pattern opposite to the buffer member, wherein the protectivelayer is formed of an inorganic material.
 8. The polarizer of claim 1,further comprising: a reflective part disposed adjacent to the linearmetal patterns, wherein the reflective part and the linear metalpatterns are formed of the same material, wherein a width of thereflective part is greater than a width of each linear metal pattern andwherein a top surface of the reflective part and a top surface of eachlinear metal pattern are positioned at the same height.
 9. The polarizerof claim 1, wherein the buffer member includes a rubber-phase buffermember and a solid-phase buffer member disposed on the rubber-phasebuffer member, and wherein the solid-phase buffer member includes aprotrusion inserted into the liner metal pattern, and wherein therubber-phase buffer member includes a polymer having a softening pointequal to or less than about 50° C., and the solid-phase buffer memberincludes a polymer having a softening point equal to or more than about100° C.
 10. The polarizer of claim 1, wherein each linear metal patternincludes a lower surface that contacts an upper surface of the buffermember and an entirely flat upper surface that opposes the lowersurface.
 11. The polarizer of claim 1, wherein the polymer of the buffermember has a softening point equal to or less than about 50° C.
 12. Apolarizer comprising: a buffer member having a plurality of protrusions,wherein the buffer member is formed of a polymer; and a plurality oflinear metal patterns spaced apart from each other and extended in afirst direction, wherein each linear metal pattern entirely covers arespective protrusion, wherein each linear metal pattern includes alower surface that contacts an upper surface of the buffer member, anentirely flat upper surface that opposes the lower surface, a pair ofnon-parallel diagonal surfaces that contact the flat upper surface and aflat portion of the buffer member between two of the protrusions,wherein a distance between a first edge of the lower surface thatcontacts one of the pair of non-parallel diagonal surfaces and a secondedge of the lower surface that contacts the other of the pair ofnon-parallel diagonal surfaces is greater than a width of the uppersurface.
 13. The polarizer of claim 12, wherein each protrusion has afirst thickness, wherein a second thickness between an upper surface ofeach linear metal pattern and an upper surface of a corresponding one ofthe protrusions is greater than the first thickness.
 14. The polarizerof claim 12, wherein the linear metal patterns include aluminum, gold,silver, copper, chromium, iron, nickel, titanium, molybdenum, tungstenor an alloy thereof.
 15. The polarizer of claim 12, wherein the buffermember includes polymethylmethacrylate, polydimethyl siloxane,polycarbonate, polyethylene terephthalate, polystyrene, polyethylene,polypropylene, polyvinylalcohol or a copolymer thereof.
 16. Thepolarizer of claim 12, further comprising a connection portion disposedbetween two adjacent linear metal patterns, wherein the connectionportion is thin to the extent that light passes through the connectionportion.
 17. The polarizer of claim 12, wherein each protrusion has adownwardly-increasing width.
 18. The polarizer of claim 12, furthercomprising: a protective layer disposed on the linear metal patternopposite to the buffer member, wherein the protective layer is formed ofan inorganic material.